Osteogenesis Imperfecta (OI) is a disease that is caused by mutation in the alpha-1 or alpha-2 genes of type I collagen. Mutations can occur in many different positions and currently there is no known correlation between position of mutation and severity of the disease. We believe that an understanding of the nature of the factors that promote stability in the collagen triple helix will give insight into the pathology of the disease. In particular we are focusing on modeling collagen-like peptides on a microscopic level. We are focusing on these issues: 1) Validating the use of molecular mechanics force fields on fibrous proteins. 2) Determining the factors that contribute to the loss in stability upon introducing mutations in model collagen-like peptides. 3) Determining the correlation between lethality of OI and structural and free energy changes induced by introduction of mutations.